Buckle with strap tightening lever



Nov. lO, 1970 H.J. BRUCKER 3,538,553

BUCKLE WITH STRAP TIGHTENING LEVER Filed 00T.. 24, 1968 2 Sheets-Sheet 1 INVENTOR. 47a Henry nl rac/ev y 75 mme/vw Nov. l0, 1970 H. J. BRucKER 3,538,553

BUCKLE WITH STRAP TIGHTENING LEVER Filed Oct. 24, 1968 wif @29 2 Sheets-Sheet 2 INVENTOR.

Henry Bracke? Y United States Patent Otiice 3,538,553 Patented Nov. l0, 1970 U.S. Cl. 24-68 5 Claims ABSTRACT F THE DISCLOSURE A buckle includes a sheet metal body section which has an apertured plate for connection to one end of a strap and also has projecting therefrom two spaced side arms ou and between which are pivotally mounted intermediate their ends the two side walls of a sheet metal strap tightening lever, which are connected together at one end by a handle plate and at the other end by a strap tensioning bar and a strap guide bar spaced apart to guide a strap between said bars and around the edge of one bar that faces oppositely from one edge of the other bar. Said bars are also closely spaced apart longitudinally of said walls and each is formed of one thickness of metal integral with and folded onto another thickness, and the folded thickness of the tensioning bar is interlocked at its ends with said side walls.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to buckles having strap tightening levers which are particularly intended for use with tiedown straps or cargo security equipment, but which have general utility.

Prior art Buckles of this general type lare shown, for example, by Pats. 2,679,670 and 2,825,109.

Such buckles comprise two sections pivotally connected together, one to be connected to, for example, one end of a strap, and the other section having cross bars related to each other and to the pivotal connection of the sections so that when the other end of the strap is threaded beween and over said cross bars, pivotal movement of the Secondmentioned section will cause a tightening of the strap.

The prior art buckles or strap or belt tightening gear either are too large or complicated or too ex-pensive in re lation to the degree of tension provided, or the degree of tension provided is so small -that the use of the buckle is limited to a relatively small area, or the design of the buckle is such that the buckle bends or warps under the average required tension so as to be practically useless.

SUMMARY An object of the present invention is to provide a buckle lin which the body section and the lever section are constructed and combined so that the buckle is capable of producing a degree of tension which is large in proportion to the small size, simplicity and low cost of the buckle.

The invention particularly contemplates a sheet metal buckle the construction of which enables the buckle to produce a large degree of tension is a strap with a minimum of danger of bending, twisting or warping of the sheet metal buckle sections and with minimum eort by the operator.

More especially the invention provides a lever section having a handle plate and side walls pivotally connected intermediate their ends to the body section and connected adjacent one end by a strap tensioning bar and a strap `guide bar each of which comprises a thickness of metal integral with and folded tightly upon another thickness and wherein the second-mentioned thickness of at least the strap tensioning bar is interlocked at its ends with said side walls so that bending or twisting of the section is reduced to the minimum.

A BRIEF DESCRIPTION OF THE DRAWINGS f For a complete understanding of the invention, reference should be had to the following description in conjunction with the accompanying drawings in which:

FIG. 1 is a top .plan View of a buckle embodying the invention with the body section and the lever section in the relative positions that are assumed when the sections are in strap tensioning position;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a transverse vertical sectional view on the plane of the line 3 3 of FIG. l;

FIG. 3a is a greatly enlarged fragmentary vertical sectional view on the plane of the line 3-3a of FIG. l;

FIG. 4 is a view similar to FIG. 3 on the plane of the line 4-4 of FIG. 1;

FIG. 5 is a fragmentary side elevational of a portion of one of the side walls of the lever section;

FIG. 6 is a plan view of the flat sheet metal blank from which the body section is formed;

FIG. 7 is a similar view of a blank of which the lever Sectio-n is made;

FIG. 7a is a sectional view approximately on the plane of the line 7-7a of FIG. 7, and

FIG. 7b is a fragmentary plan view of the side of the blank oposite that shown in FIG. 7.

FIG. 8 is a plan view of a modified at sheet metal blank from which the body section is formed;

FIG. 9 is an enlarged longitudinal sectional view of the buckle with a strap attached thereto and in released position around cartons, the strap and cartons being shown in elevation, and

FIG. 10 is a similar view with the buckle Shown in straptightening and clamping position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specifically describing the invention, the buckle includes a sheet metal body section A which has a plate 1 formed with an aperture for connection to one end of a strap and has projecting therefrom two spaced and parallel side arms 3 between which are pivotally mounted by rivets 4 the two side walls 5 of a strap-tightening lever section B, which are connected together at one end by a handle plate 6 and at the other end by a strap-tensioning bary 7 and a strap guide bar 8.

Referring to FIG. 7, it will be seen that the strap tightening lever section B is formed of a single sheet of metal which, in the forming of the section is bent along the dot and dash lines x to form the two side walls 5, and these two Walls have openings 9 through which pass the rivets 4. The blank is also folded or bent along the dot and dash lines y to form the strap guide bar 8 which thus comprises on thickness of metal integral with and folded onto another thickness. The strap-tensioning bar 7 is formed by bending or folding the blank along the dot and dash line z so that said bar also comprises one thickness of metal 7a integral with and tightly folded onto another thickness. The two bars 7 and 8 are disposed at the side of the axis of the pivotal rivets 4 opposite the handle plate `6. The fold 11 of the bar 7 forms the outer edge of the bar and faces in the opposite direction from the fold 12 of the bar 8 to form smooth rounded surfaces for the strap C when the latter is threaded through the strap tightening lever.

In accordance with the invention the folded thickness 7a of the strap-tensioning bar 7 is interlocked with the side walls 5, and as best shown in FIGS. 7a and 7b the ends of said folded thickness are provided with lugs 13.

The blank has sockets 14 into which said lugs are pressed and rrnly seated when said folded thickness of the bar is folded along the line z onto the other thickness and the blank is folded along the lines x to locate the side walls in spaced and parallel relation to each other and perpendicular to the plane of the handle plate 6.

Instead of providing the lugs 13 and the sockets 14, the ends of the folded thickness 15 may be beveled as indicated at 16 (FIG. 8) so that they bite into the side walls 5 as the latter are folded and bent into their normal spaced and parallel relation approximately perpendicular to the plane of the handle plate 6.

In use of the buckle, one end of the strap C is connected to the strap-attaching plate 1 as indicated at 17 in FIG. 9 and the two sections A and B are swung into acute angular relation to each other with the handle plate overlying the strap-attaching plate as shown in FIG. 9. Where the strap is to be used in encircling relation to a load such as the cartons D, the other end of the strap is threaded upwardly around the strap guide bar 8, thence between the bars 8 and 7 and beneath the strap-tensioning bar 7 as shown in FIG. 9, whereupon the free end of the strap is pulled to preliminarily tighten the strap around the load. Then, to tension the strap, the handle plate 6 is gripped by the hand of the operator and pulled so as to swing the lever section 8 in the clockwise direction in FIG. 9 so that the strap guide bar 8 has the strap looped around it to hold the strap as the strap-tensioning bar 7 draws the strap taut as shown in FIG. 10.

Preferably the side arms 3 of the body section and the side walls 5 of the lever section are tapered outwardly from the pivotal ends so as to lie in approvimately a common plane when the sections are in strap-tightening positions shown in FIG. 10. In this position the line of tension on the strap is between the tensioning bar 7 and the axis of the pivot 4 so that the tension tends to hold the sections in strap-tightening position. Desirably means is provided for releasably holding the sections in` this position, and such means is shown as comprising protuberances 20 which are formed on the outer surfaces of the side walls 5 when the sockets 14 are stamped in the blank, and which coact with similar protuberances 21 formed on the inner surfaces of the side arms 3.

It will be understood that the buckle may be used in many other ways, for example, in tie-down equipment where two straps are used, one having one end connected to a structure and the other end connected to the body section A of the buckle, and the other strap having one end connected to a structure and the other end threaded through the llever section B of the buckle.

An important feature of the construction is the interlocking of the folded thickness 7a of the strap-tensioning bar with the side walls 5 of the lever sections. This construction provides unexpected great strength in the bar 7 and the adjacent portions of the side walls so that the tendency toward bending or twisting of the bar or lever section during the strap-tightening operations, is reduced to the minimum. The location of the bars 7 and 8 at the side of the pivotal axis opposite the handle plate provides for highly desirable leverage which permits the buckle to produce a large degree of tension in the strap with a minimum danger of bending, twisting or warping of the buckle sections and with the expenditure of only a minimum of effort or energy by the operator.

What is claimed is:

1. A buckle comprising a sheet metal body section having an apertured strap attaching plate and two side arms projecting therefrom in spaced relation to each other, a strap-tightening lever between said side arms formed of a sheet of metal and having a handle plate at one end of the lever and two side walls projecting therefrom and pivotally connected intermediate their ends t0 said side arms, a strap-tensioning bar connecting4 said side walls at the other end of said lever, and a Strapguide bar connecting said side walls between said straptensioning bar and the pivotal axis of said sections, said pivotal axis being nearer to the second-mentioned end than to the first-mentioned end of the lever, both said bars being disposed at the same side of said pivotal axis, said strap-tensing bar and said strap guide bar being also spaced apart both longitudinally of said strap-tightening lever and transversely of the general plane of said lever, providing for the threading of a strap over said guide bar and between said bars and then over the outer edge of said strap-tensioning bar.

2. A buckle as defined in claim 1 wherein said straptensioning bar comprises a thickness of said sheet of metal integral with and folded tightly upon another thickness and wherein the lirst-mentioned thickness is interlocked with the adjacent side wall of the lever section.

3. A buckle as delined in claim 2 wherein each side wall has a socket and each end of the first-mentioned thickness of the strap-tensioning bar has a lug seated in said socket of the adjacent side wall.

4. A buckle as defined in claim 2 wherein each side wall has a socket and each end of the first-mentioned thickness of the strap-tensioning bar has a lug and said side walls have been bent from said sheet of metal into spaced parallel relation to each other and into abutment with the corresponding ends of the rst-mentioned thickness of the strap-tensioning bar with one of said lugs seated in the corresponding socket.

S. A buckle as dened in claim 2 wherein each end of the first-mentioned thickness of the strap-tensioning bar is beveled and said side walls have been bent from said sheet of metal into spaced and parallel relation t0 each other with the corresponding end of said rstmentioned thickness tightly abutting and indented into said side wall.

References Cited UNITED STATES PATENTS DONALD A. GRIFFIN, Primary Examiner 

